Improving a Basic Retrieval Method by Links and Passage Level Evidence

A conventional text retrieval method is improved by two additional sources of evidence of relevance : first, by a passage retrieval method that is based on Hidden Markov Models and second, by a so-called link method which was originally developped for hypertext retrieval. The results show that the two additional sources of evidence improve a conventional vector space retrieval method both in a consistent and in a complementary way. The link method has the ability to retrieve relevant documents whose description vectors are not very similar to the query description vector whereas the passage retrieval method has the ability to improve an existing ordering of the documents.